Well looks like I'm taking my new to me truck in

offroadman83 · July 25, 2019

Well not too happy about it but I got what seems to be two problems. I made my first payment on my truck as of today so it really hurts to possible lose it for a while. Anyways I am pretty sure its got an exhaust manifold leak and my onstar has the red dot of death or some issue. Its causing me to not have sirius (not even an icon on the radio) and the onstar won't work whatsoever. I did talk to onstar and they told me get it checked. I wasn't planning on using onstar but was planning to take advantage of the free 5 years or so diagnostics etc. Its a 2015 gmc 2500hd by the way. Anybody else have these issues?

jhplak325 · July 25, 2019

Sounds like OnStar antenna needs replaced due to water leak, this is a common problem.

as far as exhaust manifold leak, it is a common problem on the older 6.0’s, uncertain on the newer ones. Look at all the exhaust manifold bolts and see if any have broke off. I had a 2009 that had this issue.

offroadman83 · July 25, 2019

5 minutes ago, jhplak325 said:

Sounds like OnStar antenna needs replaced due to water leak, this is a common problem.

as far as exhaust manifold leak, it is a common problem on the older 6.0’s, uncertain on the newer ones. Look at all the exhaust manifold bolts and see if any have broke off. I had a 2009 that had this issue.

I looked at it yesterday and didn't see any apparent bolts broken off. Since I just glanced at it I will check it out again here in a few. Thanks--------------Kyle

offroadman83 · July 25, 2019

15 minutes ago, jhplak325 said:

Sounds like OnStar antenna needs replaced due to water leak, this is a common problem.

as far as exhaust manifold leak, it is a common problem on the older 6.0’s, uncertain on the newer ones. Look at all the exhaust manifold bolts and see if any have broke off. I had a 2009 that had this issue.

Wouldn't you know it I went outside to look at it again more in detail and I noticed a missing bolt head on the the very first bolt on the drivers side manifold.............oh well in it goes. Thank God I ponied up for extended warranty...........

SierraHD17 · July 26, 2019

Yeah the bolts still suck and break off lol. A person can put in grade 8 hardware and it might stand up better... maybe. It's honestly easier to just swap the bolts out one by one every once and while lol. Sounds stupid but the alternative is even more stupid to deal with lol. Even once they fix it the truck will do it again... and again and again lol.

offroadman83 · July 26, 2019

1 hour ago, SierraHD17 said:

Yeah the bolts still suck and break off lol. A person can put in grade 8 hardware and it might stand up better... maybe. It's honestly easier to just swap the bolts out one by one every once and while lol. Sounds stupid but the alternative is even more stupid to deal with lol. Even once they fix it the truck will do it again... and again and again lol.

Well that sucks....

Colossus · July 26, 2019

Yes it does. I can't believe GM is still having this issue and hasn't corrected it by now. The 6.0 was doing this since its release. other than this, the 6.0 has been very durable and reliable.

offroadman83 · July 26, 2019

Well they are scheduled to fix it on Wednesday and im probably gonna order the manifold fix brackets from Kral auto to have. Dont know if ill wait to see if its fixed or what. Kind of wish i could just use the brackets since they seem to be a permanent fix but i guess ill trust the dealership to fix it.

davester · July 27, 2019

I bought and installed the dorman exhaust clamps, and they work/fit fine for me (3 of the 4 end bolts were broken off and sucked to get out).

offroadman83 · July 27, 2019

11 hours ago, davester said:

I bought and installed the dorman exhaust clamps, and they work/fit fine for me (3 of the 4 end bolts were broken off and sucked to get out).

I would probably buy dorman but they do not have anything for the front drivers side strangely enough which is where mine is broken.

MNorby · July 29, 2019

If you have a welder its really not too bad to replace the broken ones yourself, at least on the older trucks, haven't had the pleasure to do the newer ones yet. On a 2005 just taking the tire and wheel liner off gave plenty of room to weld a nut to what was left of the broken bolt and take it out. Did 3 on one side and 2 on the other on that truck. The 2001 6.0 for my rock crawler had 3 broken total as well.

offroadman83 · July 31, 2019

On 7/29/2019 at 2:10 PM, MNorby said:

If you have a welder its really not too bad to replace the broken ones yourself, at least on the older trucks, haven't had the pleasure to do the newer ones yet. On a 2005 just taking the tire and wheel liner off gave plenty of room to weld a nut to what was left of the broken bolt and take it out. Did 3 on one side and 2 on the other on that truck. The 2001 6.0 for my rock crawler had 3 broken total as well.

I probably would just do it myself but im paying for that warranty anyways so might as well use it lol.

MNorby · July 31, 2019

1 hour ago, offroadman83 said:

I probably would just do it myself but im paying for that warranty anyways so might as well use it lol.

For sure use the warranty but I would just replace the broken bolts before using those clamping devices if you have access to a welder.

SierraHD17 · August 2, 2019

On 7/25/2019 at 11:05 PM, Colossus said:

Yes it does. I can't believe GM is still having this issue and hasn't corrected it by now. The 6.0 was doing this since its release. other than this, the 6.0 has been very durable and reliable.

Its thermal expansion. All LS's do it... 4.8's, 5.3's, 6.2's etc. Its not unique to the 6 liter. It's all about heat cycling and the harder you work it the more stress the bolts are under. I imagine the LT series will do it too. Fords do it... Rams... etc. Cast iron expands when it's hot and shrinks when it's cold and eventually something has to give.

offroadman83 · August 2, 2019

Well I got it back today......its fixed at least and Im happy for now and most importantly glad to have it back. Love this truck!!

Guess i spoke too soon....gave me a code and stumbled real bad. Gave me a code that said p303 so i checked the 3rd cylinder area wires, coils plugs and nada. Going back to the damn shop.

Edited August 4, 2019 by offroadman83